In the currently liquid crystal display device, commonly used white LED (Light-Emitting Diode) as a backlight source. The most popular white LED is the LED of the blue emitting chip adding the yellow YAG (Y3A15O12, Yttrium aluminum garnet) phosphor, after using the LED of the yellow phosphor material to match the LCD screen, the color saturation is low and the color of the display is not colorful enough.
Refer to FIG. 1, FIG. 1 is a color saturation contrast schematic of the RG phosphor and the YAG phosphor in the background of the present disclosure, it can be seen from the figure. In comparison of the LED of the YAG phosphor, because the LED backlight of the RG phosphor is narrower by the spectrum FWHM (full-width-at half-maximum) of the R and G pixel, the R and G color is more pure and is possible to achieve higher color saturation.
In order to increase the color saturation, usually by the yellow phosphor change to the RG (red and green) phosphor, but this approach requires the replacement of the existing liquid crystal display LED device can no longer direct promote the color gamut based on the existing light source.
Currently in high color saturation LCD backlight technology, the color gamut can reach the highest is quantum dot material containing Cd (cadmium) element, since the Cd has a very big impact on human health and the quantum dot film is very expensive, the development of the high color saturation technology without Cd and with low cost is the trend of the development of the high color saturation of the LCD device.